Can Offshore Wind Energy And Fishing Coexist?

How can offshore wind and commercial fishing co-exist alongside each another?

As society explores opportunities in marine renewable energy, these new uses of the ocean must be balanced with fishing and other traditional uses. Fishermen and other ocean community stakeholders will play a key role in shaping the future of ocean energy development.

The intersection of ocean energy production and fisheries management raises questions of both science and policy. Factually, how will ocean energy development affect commercial fisheries? Some evidence suggests that offshore wind projects — whether mounted on the sea floor or floating on offshore platforms — may not harm fisheries. For example, a before-and-after study of the Danish Horns Rev project found “no general significant changes in the abundance or distribution patterns of pelagic and demersal fish” seven years after project construction.

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Projects could even enhance fisheries as manmade structures may serve as habitat, attracting sea-life like natural reefs do. Proponents of offshore wind argue that properly designed offshore wind structures could both boost fish populations and enhance opportunities to catch valuable species.

Others worry that offshore wind projects will harm fish populations and the human dependent on them. Whether and how each wind tower is mounted on the sea bed may impact groundfish; the noise and acoustic pressure created by pile-driving can affect fish and marine mammals. Even deepwater floating offshore wind platforms will likely be moored to the sea floor in some manner.

Sea bed habitat may also be impacted by the installation of the submarine cables needed to connect each generator to electrical substations, as well as by the cables needed to transmit that power ashore. These cables may limit fishermen’s ability to trawl the bottom in the affected area, and their electromagnetic fields could affect marine species.

An offshore wind project may also impact fisheries through increased marine traffic, from heavy construction vessels to ships needed to service the project. At the same time, fishermen may be excluded from the areas within or near a project; depending on their design and applicable regulations, offshore wind projects may require setback areas or safety zones. Tall towers may also limit the usefulness of radar, critical to safe navigation in foggy waters.

These concerns have led some fishermen and trade associations to oppose offshore wind development. Some may be resolved through science, whether by documenting projects’ effects on fish populations or by designing project elements to minimize those impacts. Others fall more squarely in the realm of policy.

Oceans have provided humans sustenance for millennia — some archaeological evidence suggests deep-sea fishing as early as 42,000 years ago, and most of the U.S. continental shelf supports fisheries and other non-energy marine uses.

To the extent that offshore wind projects affect fisheries — meaning both the fish and the people who catch them — policy decisions must be made that balance these interests.